Pulse-producing electrical switch

ABSTRACT

A snap action pulse-producing electrical switch comprises a carrier means operatively connected to a support and movable relative to the support from first position to second position upon the application of an actuating force thereto, a first electrical contact operatively connected to the carrier means and movable therewith, a second electrical contact positioned to receive the first contact in an electrical connection, and snap means operatively connected to the first contact and effective to snap the first contact into engagement with the second contact when the first contact is moved past a predetermined position between its nonactuated first position and the engagement with the second contact. The snap means are also effective to quickly disengage the contacts after the engagement occurs, and to urge the first contact and the carrier to their respective first positions. In the preferred embodiment the snap means comprises a flexible member which is normally flexed in a first condition, and which snaps to a second flexed condition when the contact passes a predetermined position in its travel. A resilient member provides additional force generation during the snap-over action of the flexible member. The resilient member is in operative contact with a stationary member and moves in the direction of travel of the first contact. The resilient member is also flexed from one condition to another simultaneously with the flexible member, thereby to provide additional snap driving means.

United States Patent [72] Inventor Robert N. Nanninga Canoga Park, Calif.

[21] Appl. No. 879,990

[22] Filed Nov. 26, 1969 [45] Patented Jan. 4, 1972 [73] Assignee Industrial Electronic Hardware New York, N.Y.

[54] PULSE-PRODUCING ELECTRICAL SWITCH Primary Examiner-Jones H. 0. Assistant Examiner-Robert A. Vanderhye AttorneyJames and Franklin ABSTRACT: A snap action pulse-producing electrical switch comprises a carrier means operatively connected to a support and movable relative to the support from first position to second position upon the application of an actuating force thereto, a first electrical contact operatively connected to the carrier means and movable therewith, a second electrical contact positioned to receive the first contact in an electrical connection, and snap means operatively connected to the first contact and effective to snap the first contact into engagement with the second contact when the first contact is moved past a predetermined position between its nonactuated first position and the engagement with the second contact. The snap means are also effective to quickly disengage the contacts after the engagement occurs, and to urge the first contact and the carrier to their respective first positions. In the preferred embodiment the snap means comprises a flexible member which is normally flexed in a first condition, and which snaps to a second flexed condition when the contact passes a predetermined position in its travel. A resilient member provides additional force generation during the snap-over action of the flexible member. The resilient member is in operative contact with a stationary member and moves in. the direction of travel of the first contact. The resilient member is also flexed from one condition to another simultaneously with the flexible member, thereby to provide additional snap driving means.

PULSE-PRODUCING ELECTRICAL SWITCH This invention relates to electrical switches, and more specifically to a snap action switch which is designed to produce an electrical signal in the form of a pulse.

Recent developments in the electronics field, particularly in computer technology, have called for highly advanced electrical switches. Switching speeds on the order of nanoseconds are necessary for the proper operation of the high-speed computers. This fast switching is effected in electrical circuits without the use of any moving mechanical parts bymeans of such devices as semiconductors arranged in various gating circuits. Fast speed switching in electromechanical and mechanical devices is considerably slower than in electronic devices.

Despite the relatively slow speed of mechanical switches, there are still a wide variety of applications in which they are important. One example is an electric typewriter in which printing is directly related to the actuation of an electromechanical switch by manual means, such as the depres sion of a typewriter key. As is well known, an electrical typewriter converts the mechanical displacement of a key into an electrical pulse signal which is then reconverted into a mechanical movement, i.e., printing. It is imperative in this type of device that the components which are employed be capable of fast operation. Obviously, the speed at which the complete printing operation occurs is limited by the mechanical movement of the various parts in the system.

Even though some mechanical switches have been developed which are capable of operating to produce electrical pulses quickly, the quality of the pulse is often adversely affected by vibrational conditions during the operation of the switch. Thus it is not uncommon for switches of the type now available to produce double pulses or half pulses because of the vibrational shock experienced by the switch during its operation. In addition, the presently available high-speed switches are usually quite large and are expensive to manufacture.

It is the primary object of this invention, therefore, to provide a switch which quickly and accurately produces an electrical pulse in response to a mechanical movement.

It is another object of this invention to provide a snap action switch which when once actuated, quickly and automatically resumes its initial operative position so as to be prepared for the next operative cycle.

A further object of this invention is to provide a snap action switch which is characterized by its miniature size.

The objects of the invention are achieved by a snap action electrical switch which comprises a support member, carrier means operatively connected to the support member and movable relative thereto from a first position to a second position upon the application of an actuating force to the carrier means, a first electrical contact operatively connected to the carrier means and movable therewith from a first position to a second position, a second electrical contact operatively connected to the support member and effective to engage the first contact when the latter is at its second position, and snap means operatively connected to the first contact and effective to snap the first contact into engagement with the second contact when the first contact is moved past a predetermined position between its first and second positions. Snap switches are old, but when these prior art switches are snapped to one position, thereby, for example, to close a circuit, they tend to remain in that position. They produce a continuing signal, not a pulse. The switch of the present invention, however, produces a pulse rather than a continuing signal. It does this because the snap means is also effective to automatically and quickly snap the first contact out of engagement with the second contact after the engagement has been effected and to urge the first contact and the carrier to their original positions, thereby to restore the switch to its original condition. Thus a single manual actuation causes engagement and then disengagement of the contacts.

In the preferred embodiment, the snap means comprises a flexible member which is operatively attached at one part to the support member and operatively connected at a second part to the carrier. The carrier is adapted to be manually moved. The first contact is operatively connected to the flexible member so as to be movable therewith. The flexible member snaps from a first flexed condition to a second flexed condition as its second part. moving with the carrier, passes a predetermined position. The change is flexed condition of the flexible member is effective to cause acceleration of the first contact and quick engagement thereof with the second contact. The flexible member is so designed that it tends to snap back to its original flexed condition immediately after the first contact engages the second contact. As a result, only a brief engagement of the two contacts occurs.

In one form of the invention the flexible member comprises an elongated strip of resilient material so positioned between the support means and the carrier as to form a convex curvature when viewed from above in one of the flexed conditions and to snap over into a concave curvature in the other of the flexed conditions.

In order to assist the flexible member during the transition from one to another flexed condition, additional components are employed. A stationary member is operatively connected to the support and extends in the direction of movement of the carrier from its first position to its second position. The stationary member is characterized by a. first part with a given width dimension measured in a direction substantially normal to the direction of axial extension of the member and an ad jacent second part having a reduced width dimension relative to that of the first member. A resilient member such as a garter spring encloses the stationary member and is connected to the carrier member so as to be moved. over the surface of the stationary member as the carrier is manually moved. The garter spring is expanded during its movement over the first part of the stationary member and contracted quickly as it passes to the adjacent reduced second part. The junction of the first and second part on the stationary member is so located that the chance in flexed condition of the garter spring, that is from its expanded to its contracted state, occurs substantially simultaneously with the snap change in flexed condition of the flexible member to which the first contact is attached. Thus, the first contact is snapped simultaneously by both the flexible member, i.e., the elongated resilient strip, and by the passage of the garter spring over the tapered stationary member. In this manner, frictional resistance at the joints between connected components and the mass of these components are readily overcome and a snap action is assured.

While the force generated by the flexible member is generally sufficient to urge the first contact back to its first position after engagement with the second contact, additional spring means is included between the carrier and the support to ensure that the mass of the carrier is overcome when disengagement of the contacts is effected. This spring, which is compressed by the carrier in its advanced travel between its first and second positions, generates sufficient spring force when released to urge the carrier and thus the first contact to return to their original nonactuated positions. With the use of such a return spring the immediate disengagement of the contacts is also assured notwithstanding the frictional forces at the joints of the interconnected components and the mass of the several moving parts.

The manually actuated means may take the form of a movable button and depending flanged part operatively connected to the carrier and effective to move the carrier from its first position, that is, its normal nonactuated position, to its second position, that is, the position at which the first contact engages the second contact. The flanged part of the button normally engages the carrier means so that the carrier and the first contact connected thereto may be separated from the button when they are snapped from the first flexed condition to the second flexed condition. A return spring is operatively connected to the actuated means and is effective to return it to its initial position upon the removal of the actuating force therefrom. The actuating force is generally only momentarily applied to the button, and need only be of a sufficient amplitude, direction, and duration to cause the carrier to reach the predetermined snap-over position in its travel between its first and second positions.

To the accomplishment of the foregoing, and to such other objects as may hereinafter appear, the present invention relates to the construction of a snap action switch as defined in the appended claims, and as described in this specification taken together with the accompanying drawing in which:

FIG. 1 is a front elevational view in cross section of the snap action switch of the invention in its nonactuated position.

FIG. 2 is a front elevational view in cross section of the snap action switch of the invention in its actuated condition; and

FIG. 3 is a cross-sectional view taken on the line 3-3 of FIG. 1.

Referring to FIG. I, a snap action switch generally designated is shown in its normal nonactuated condition. The switch includes a support structure 12 which in the illustrated embodiment encloses the main switch components. A carrier member generally designated 14 is operatively movable within the support 12 from a first position (FIG. 1) to a second position (FIG. 2). A pair of electrical contacts 16 and 18 are carried by snap means generally designated 20, and are moved with the carrier member 14 when it advances from its first position to its second position due to the operative connection of the snap means 20 to the carrier member 14 at carrier recesses 19 and 21. The carrier member 14 is advanced by an actuating means generally designated 22 which comprises a button 23 and a laterally extending part 24. The part 24 engages the upper surface 25 of the carrier member 14 in the nonactuated position, and is effective to force the carrier member 14 downward as an actuating force in the direction of arrow 26 is applied to the button 23. The button is movable within the opening 28 of the support 12.

In the condition illustrated in FIG. 1, the first and movable contacts 16 and 18 are in engagement with the electrical fixed contacts 30 and 32 respectively. The output leads 34, 35 and 36, 37 are respectively electrically connected to the contacts 16, 18 and contacts 30, 32. The snap means 20 is generally composed of an electrically conducting material, and therefore in the position shown the output leads 34, 35 are connected to output leads 36, 37 respectively. As hereinafter more fully explained, when an actuating force is applied to the button 23, the contacts 16 and 18 are disengaged from the contacts 30 and 32, and are caused to momentarily engage contacts 38 and 40, as shown in FIG. 2. When this occurs, output leads 42 and 43 are connected to output leads 34 and 35 respectively. This is referred to as the actuating position of the switch 10. The switch 10 is thus shown as a souble pole, double throw switch.

During the change in position of contacts 16 and 18 from the position of FIG. 1 to that of FIG. 2, the snap means 20 is effective to snap these movable contacts into engagement with fixed contacts 38 and and to quickly urge the contacts out of engagement once the connection has been made. To this end, the snap means 20 preferably comprises a pair of elongated flexible members 44 and 46 (FIG. 3). These members are operatively connected at one end to the support 12 such as at joints 48 and 50. The other end of members 44 and 46 are operatively attached to the carrier 14 in recessed areas 19 and 21. The flexible members 44 and 46 are therefore movable with the carrier 14 as it is advanced from its first position by the action of the force 26 applied to the button 23. These members 44 and 46 are flexed in one condition (FIG. 1) to form a convex curvature when viewed from above (FIG. 3). This is the normal condition of these members. As these flexible members 44 and 46 are caused to move toward contacts 38 and 40, however, a position is reached at which these members will flex to a second condition of opposite (concave) curvature as shown in FIG. 2. The change in flexed condition occurs rapidly as these members 44 and 46 pass this position, hereinafter referred to as the snap-over position. The fixed contacts 38 and 40 are positioned, however, to intercept contacts 16 and 18 during this accelerated snap-over position. Since the members 44 and 46 are structured to normally assume the position shown in FIG. I, that is, they are arched concavely during the fabrication of the switch, they are effectively spring biased to return to this condition after the change in flexed condition occurs provided they do not travel too far beyond the snap-over position. As a result, the members 44 and 46 are immediately resiliently urged back to the original condition shown in FIG. 1. Thus, only a momentary engagement of contacts 16 with 38 and 18 with 40 occurs before the disengagement of these contacts is effected by the return snap action of member 44 and 46.

The snap-over position for these members is a function of a number of factors, including the extent of initial curvature of the members 44 and 46, the distance travelled by the movable end of these members, and the degree of flexibility of the material employed for these members. The flexible character of the members is directly related to the specific material selected and the thickness thereof. Since the members are generally current carrying components, consideration thereof must be made also during the fabrication and selection of these members. Materials such as phosphor bronze and beryl lium copper of a thickness of several thousandths of an inch and approximately one quarter inch wide are quite suitable for both the flexibility and current carrying capacity required in members 44 and 46.

The members 44 and 46 are initially flat strips of material and are formed into an arched configuration during the formation of the switch. Thus the degree of curvature may readily be varied by varying the initial length of the members, so that as manufactured they are slightly longer than the distance between the connection points of these members in the nonactuated condition of the switch i.e., the distance between recess 19 and junction 48 for member 44 between recess 21 and junction 50 for member 46. The members are thereby placed under a pressure which imparts the snap resiliency thereto which is important to the proper operation of the switch. By a proper design of the members, therefore, the snap-over position will be located at a position between the first position of the contacts 16 and 18 (FIG. 1) and the second position of these contacts (FIG. 2).

The snap action of the members 44 and 46 is analogous to the action which occurs in the well known commercially available finger actuated noisemaker device which employs a flexible, resilient strip of metal projecting angularly form a part adapted to be manually held. This common variety of noisemaker clicks from one flexed condition to another up on the application of an actuating force (such as pressure applied by the thumb) to the movable end of the strip. Upon the release of this force i.e., removal of the actuating finger, the strip clicks back to its initial position. Similarly the members 44 and 46 in the switch 10 snap from the first position to the second position and then return to the first position when the actuating force is removed.

While the members 44 and 46 are effective to snap the contacts 16 and 18 into and out of engagement with contacts 38 and 40, additional force generating devices are provided to assist these members during this part of the operating cycle. Thus, the snap means 20 may further include a stationary member 56 which is operatively connected to the support 12 at the joint 58 and extends in the direction of movement of the carrier 14. The member 56 is characterized by a tapered outer surface 60 which includes a first tapered section 62 and on oppositely tapered second section 64. A garter spring 66 en closes the member 56 and is held between the extending parts 67 and 69 of the carrier 14. This garter spring 66 is engaged by the parts 67 and 69 and moved with the carrier 14 as it travels from its first position to its second position and back to its first position. The garter spring expands as it moves over the increasing taper of section 62, until it reaches the junction 68 which is shown substantially at the central point of the member 56. As it passes this junction 68 garter spring 66 quickly contracts while moving over the decreasing taper of section 62. The force generated by the garter spring on the carrier 14 during this latter motion is such as to assist the members 44 and 46 during their change of flexed condition from the nonactuated to the actuated positions. This supplemental snap is employed to overcome the mass of the carrier 14 and frictional forces in the system between the interconnected components.

A return spring 70 also functions as an additional force generating device in the switch to aid the members 44 and 46 to return to their original condition. This spring 70 is at one end in the recessed area 72 of the support 12, and at the other end engages the surface 74 of the carrier 14. The spring 70 is compressed by the manual force 26 during the advance of the carrier 14 and is released when the members 44 and 46 urge contacts I6 and 18 back to their first position, that is, after the momentary engagement of contacts l6, 18 with contacts 38, 40 respectively. The snap return action of this spring 70 acts upon carrier 14 and supplements the return force provided by the members 44 and 46 immediately after the engagement of the contacts.

In the preferred form of the switch of the invention, the ac tuating button 23 and the flanged part 24 are disengageable from the carrier 14 at the snap-over position of the member 44 and 46. This disengagement is illustrated by the space 75 in FIG. 2. The actuating means 22 may be returned to its original position upon the removal of an actuating force by means of a return spring 76. The spring 76 at one end engages the inner surface 78 of the button 23, and its other end engages the supporting member 80 which is operatively connected to the stationary member 56. Since the spring 76 is compressed between the surface 78 and the member 80 during the advance of the button 23, it forces the button and therefore the flanged part 24 back to the normal position shown in FIG. I upon release of the actuating force 26 from the button. The actuating means 22 is therefore in a condition for the next actuation cycle. The carrier 14 is also thereby able to return to its original position also illustrated in FIG. ll, since the flanged part 24 has already returned. In the actual operation of the switch, the return actuation of all of the components occurs substantially simultaneously since the actuating force may immediately be removed upon the change in flexed condition of the members 44 and 46.

The contacts l6 and 18 as well as the contacts 38 and 40 are preferably composed of a wear-resistant electrically conductive material. A suitable material of this type includes tungsten impregnated with silver. The contacts 16 and 18 should project from the members 44 and 46 a distance sufficient for these contacts to engage contacts 38 and 40 during the snapover of members 44 and 46.

The snap-action switch herein described is capable of producing a momentary engagement of contacts in the order of approximately 4 milliseconds, thereby producing a pulse of that duration at the output terminals 42 and 43. The am plitude of this pulse is dependent upon the external circuitry and the electrical capacity of the switch itself. The switch may be designed to handle voltages in the order of 120 volts AC and 28 volts DC, as well as currents of an amplitude of approximately 30 amperes.

One of the important advantages of the switch shown is that it may be fabricated in a miniature size. The switch has been manufactured having dimensions of no greater than 1% inch in width and 1 inch in height. Such a miniature switch is readi ly adapted for use in a wide variety of industrial applications, of which an electric typewriter is but one.

Adjustment of the actuating force necessary to flex the members 44 and 46 from one condition to another may readily be accomplished with the switch of the invention. Actuating forces over a wide range may be provided by simply adjusting the spring tension inherent in return springs 70 and 76. Thus, varying customer requirements for specific industrial applications may readily be satisfied by a mere substitution of spring components.

When the switch is sued in an electric typewriter, a stop mechanism of any suitable type may be provided to prevent the overtravel of the actuating means during the depression of a typewriter key. The stop mechanism may be positioned to permit the carrier to be advanced to the snap-over position and thereafter the switch automatically provides a pulse as above explained. Thus continued pressure on the key has no adverse effect on the pulse producing operating of the switch. Furthermore, the switch is so structured as to enable the typist to operate all of the keys with a uniform and light finger pressure.

While only one embodiment of the invention has herein been described, many modifications thereof may be made without departing from the scope of the invention.

Iclaim:

l. A snap action electrical switch comprising a :iupport means, carrier means, carrier actuating means, said carrier means being operatively connected to said support means and said carrier actuating means and movable relative to said support means from a first position to a second position upon the application of an actuating force to said carrier actuating means, first electrical contact means operatively connected to said carrier means and movable therewith from a first position to a second position, second electrical contact means operatively connected to said support means and effective to engage said first contact means when the latter is at said second position, and snap means operatively connected to said first contact means and effective to snap said first contact means into engagement with said second contact means when said first contact means is moved past a predetermined position between its first and second positions, and thereafter, without the application of additional actuating force to said carrier actuating means, once said engagement has been effected, to automatically urge said first contact means out of engagement with said second contact means to urge said first contact means and said carrier means to their respective first positions, said snap means comprising a flexible member operatively attached a first part thereof to said support means and at a second part thereof operatively connected to said carrier means, said flexible member snapping from a first flexed condition to a second flexed condition at said predetermined position of said first contact means, thereby snapping said first contact means into engagement with said second contact means, and tending tosnap from said second condition to said first condition upon engagement of said first contact means and said second contact means thereby to urge said first contact means away from said second contact means, said snap means further comprising a stationary member operatively connected to said support structure means and extending in the direction of movement of said carrier means from its first position to its second position, said member having a first part with a given width dimension measured in a direction substantially normal to the direction of said extension of said member, and an adjacent second part having a reduced width dimension relative to that of said first part, and a resilient member in operative engagement with said stationary member and operatively connected to said carrier means, said resilient member being moved over said stationary member by said carrier means, and being snapped form one flexed condition to a second flexed condition during its movement from said first part to said second part of said stationary member, said first and second parts of said stationary member being joined at a location such that said resilient member is snapped substantially simultaneously with the snap of said flexible member from its first condition to its second condition.

2. The switch of claim 1, in which said flexible member comprises an elongates strip of material, said strip when viewed from above forming a convex curvature in one of said flexed conditions and a concave curvature in the other of said flexed conditions.

3. The switch of claim 1, in which said resilient member comprises a spring substantially surrounding said stationary member, said spring being expanded over said first part of said stationary member when said carrier means moves from its first position toward its second position, and being contracted over said second part of said stationary member upon the continued movement of said carrier means.

4. In the switch of claim 1, first spring means operatively connected to said support means and to said carrier means and effective to aid in returning said carrier means, said resilient member, and said first contact means to their respective normal first positions after said first contact means engages said second contact means.

5. In the switch of claim 4, third electrical contact means positioned at the first position of said first electrical contact means, said third electrical contact means being engaged by said first contact means when the latter is in its said first position, thereby to provide an electrical connection therewith.

6. A snap action electrical switch comprising a support means, carrier means, carrier actuating means, said carrier means being operatively connected to said support means and said carrier actuating means and movable relative to said support means from a first position to a second position upon the application of an actuating force to said carrier actuating means, first electrical contact means operatively connected to said carrier means and movable therewith from a first position to a second position, second electrical contact means operatively connected to said support means and effective to engage said first contact means when the latter is at said second position, and snap means operatively connected to said first contact means and effective to snap said first contact means into engagement with said second contact means when said first contact means is moved past a predetermined position between its first and second positions, and thereafter, without the application of additional actuating force to said carrier actuating means, once said engagement has been effected, to automatically urge said first contact means out of engagement with said second contact means and to urge said first contact means and said carrier means to their respective first positions, said carrier actuating means comprising an actuating member engaging said carrier means and effective upon the application of an actuating force thereto to move said carrier means from its first position toward its second position, said actuating member being disengageable from said carrier means when said first contact means is snapped into engagement with said second contact means.

7. In the switch of claim 6, spring means operatively connected to said actuating member and effective to automatically return said actuating member to its first position upon the removal of an actuating force therefrom.

8. A snap action electrical switch comprising a support means, carrier means, carrier actuating means, said carrier means being operatively connected to said support means and said carrier actuating means and movable relative to said sup port means from a first position to a second position upon the application of an actuating force to said carrier actuating means, first electrical contact means operatively connected to said carrier means and movable therewith from a first position to a second position, second electrical contact means operatively connected to said support means and effective to engage said first contact means when the latter is at said second position, and snap means operatively connected to said first contact means and effective to snap said first contact means into engagement with said second contact means when said first contact means is moved past a predetermined position between its first and second positions, and thereafter, without the application of additional actuating force to said carrier actuating means, once the engagement has been effected, to automatically urge said first contact means out of engagement with said second contact means and to urge said first contact means and said carrier means to their respective first positions, said snap means comprising a flexible member operatively attached at a first part thereof to said support means and at a second part thereof operatively connected to said carrier means, said flexible member snapping from a first flexed condition to a second flexed condition at said predetermined position of said first contact means, thereby snapping said first contact means into engagement with said second contact means, and tending to snap from said second condition to said first condition upon engagement of said first contact means and said second contact means thereby to urge said first contact means away from said second contact means, said flexible member comprising an elongated strip of material, said strip when viewed from above forming a convex curvature in one of said flexed conditions and a concave curvature in the other of said flexed conditions, said snap means further comprising a stationary member operatively connected to said support structure means and extending in the direction of movement of said carrier means from its first part with a given width dimension measured in a direction substantially normal to the direction of said extension of said member, and an adjacent second part having a reduced width dimension relative to that of said first part, and a resilient member in operative engagement with said stationary member and operatively connected to said carrier means, said resilient member being moved over said stationary member by said carrier means, and being snapped from one flexed condition to a second flexed condition during its movement from said first part to said second part of said stationary member, said first and second parts of said stationary member being joined at a location such that said resilient member is snapped substantially simultaneously with the snap of said flexible member from its first condition to its second condition.

9. The switch of claim 8, in which said resilient member comprises a spring substantially surrounding said stationary member, said spring being expanded over said first part of said stationary member when said carrier means moves from its fist position toward its second position, and being contracted over said second part of said stationary member upon the continued movement of said carrier means.

10. The switch of claim 9, in which said carrier actuating means comprises an actuating member engaging said carrier means and effective upon the application of an actuating force thereto to move said carrier means from its first position toward its second position, said actuating member being disengageable from said carrier means when said first contact means is snapped into engagement with said second contact means.

11. In the switch of claim 10, fist spring means operatively connected to said support means and to said carrier means and effective to aid in returning said carrier means, said resilient member, and said first contact means to their respective normal first positions after said first contact means engages said second contact means.

12. A snap action electrical switch comprising a support means, carrier means operatively connected to said support means and movable relative to said support means from a first position to a second position upon the application of an actuating force thereto, said electrical contact means operatively connected to said carrier means and movable therewith from a corresponding first position to a corresponding second position, second electrical contact means operatively connected to said support means and effective to engage said first contact means when the latter is at said second position, and snap means operatively connected to said first contact means and effective to snap said first contact means into engagement with said second contact means when said first contact means is moved past a predetermined position between its first and second positions, said snap means comprising a flexible member operatively connected at a first part thereof to said support means and at a second part thereof operatively connected to said carrier means, said flexible member snapping from a first flexed condition corresponding to said first position of said first contact means to a second flexed condition corresponding to said second position of said first contact means, said snapover occuring at said predetermined position of said first contact means, thereby snapping said first contact means into engagement with said second contact means, said first contact means engaging said second contact means at a position sufficiently close to said predetermined snapover position such that said flexible member tends to automatically snap back from said second flexed condition to said first flexed condition upon engagement of said first contact means and said second contact means, thereby to urge said first contact means out of engagement with said second contact means and to urge said first contact means and said carrier means to their respective first positions.

13. The switch of claim 12, in which said carrier actuating means comprises an actuating member engaging said carrier means and effective upon the application of an actuating force thereto to move said carrier means from its first position toward its second position, said actuating member being disengageable from said carrier means when said first contact means is snapped into engagement with said second contact means.

after said first contact means engages said second contact means. 

1. A snap action electrical switch comprising a support means, carrier means, carrier actuating means, said carrier means being operatively connected to said support means and said carrier actuating means and movable relative to said support means from a first position to a second position upon the application of an actuating force to said carrier actuating means, first electrical contact means operatively connected to said carrier means and movable therewith from a first position to a second position, second electrical contact means operatively connected to said support means and effective to engage said first contact means when the latter is at said second position, and snap means operatively connected to said first contact means and effective to snap said first contact means into engagement with said second contact means when said first contact means is moved past a predetermined position between its first and second positions, and thereafter, without the application of additional actuating force to said carrier actuating means, once said engagement has been effected, to automatically urge said first contact means out of engagement with said second contact means and to urge said first contact means and said carrier means to their respective first positions, said snap means comprising a flexible member operatively attached at a first part thereof to said support means and at a second part thereof operatively connected to said carrier means, said flexible member snapping from a first flexed condition to a second flexed condition at said predetermined position of said first contact means, thereby snapping said first contact means into engagement with said second contact means, and tending to snap from said second condition to said first condition upon engagement of said first contact means and said second contact means thereby to urge said first contact means away from said second contact means, said snap means further comprising a stationary member operatively connected to said support structure means and extending in the direction of movement of said carrier means from its first position to its second position, said member having a first part with a given width dimension measured in a direction substantially normal to the direction of said extension of said member, and an adjacent second part having a reduced width dimension relative to that of said first part, and a resilient member in operative engagement with said stationary member and operatively connected to said carrier means, said resilient member being moved over said stationary member by said carrier means, and being snapped form one flexed condition to a second flexed condition during its movement from said first part to said second part of said stationary member, said first and second parts of said stationary member being joined at a location such that said resilient member is snapped substantially simultaneously with the snap of said flexible member from its first condition to its second condition.
 2. The switch of claim 1, in which said flexible member comprises an elongated strip of material, said strip when viewed from above forming a convex curvature in one of said flexed conditions and a concave curvature in the other of said flexed conditions.
 3. The switch of claim 1, in which said resilient member comprises a spring substantially surrounding said stationary member, said spring being expanded over said first part of said stationary member when said carrier means moves from its first position toward its second position, and being contracted over said second part of said stationary member upon the continued movement of said carrier means.
 4. In the switch of claim 1, first spring means operatively connected to said support means and to said carrier meAns and effective to aid in returning said carrier means, said resilient member, and said first contact means to their respective normal first positions after said first contact means engages said second contact means.
 5. In the switch of claim 4, third electrical contact means positioned at the first position of said first electrical contact means, said third electrical contact means being engaged by said first contact means when the latter is in its said first position, thereby to provide an electrical connection therewith.
 6. A snap action electrical switch comprising a support means, carrier means, carrier actuating means, said carrier means being operatively connected to said support means and said carrier actuating means and movable relative to said support means from a first position to a second position upon the application of an actuating force to said carrier actuating means, first electrical contact means operatively connected to said carrier means and movable therewith from a first position to a second position, second electrical contact means operatively connected to said support means and effective to engage said first contact means when the latter is at said second position, and snap means operatively connected to said first contact means and effective to snap said first contact means into engagement with said second contact means when said first contact means is moved past a predetermined position between its first and second positions, and thereafter, without the application of additional actuating force to said carrier actuating means, once said engagement has been effected, to automatically urge said first contact means out of engagement with said second contact means and to urge said first contact means and said carrier means to their respective first positions, said carrier actuating means comprising an actuating member engaging said carrier means and effective upon the application of an actuating force thereto to move said carrier means from its first position toward its second position, said actuating member being disengageable from said carrier means when said first contact means is snapped into engagement with said second contact means.
 7. In the switch of claim 6, spring means operatively connected to said actuating member and effective to automatically return said actuating member to its first position upon the removal of an actuating force therefrom.
 8. A snap action electrical switch comprising a support means, carrier means, carrier actuating means, said carrier means being operatively connected to said support means and said carrier actuating means and movable relative to said support means from a first position to a second position upon the application of an actuating force to said carrier actuating means, first electrical contact means operatively connected to said carrier means and movable therewith from a first position to a second position, second electrical contact means operatively connected to said support means and effective to engage said first contact means when the latter is at said second position, and snap means operatively connected to said first contact means and effective to snap said first contact means into engagement with said second contact means when said first contact means is moved past a predetermined position between its first and second positions, and thereafter, without the application of additional actuating force to said carrier actuating means, once said engagement has been effected, to automatically urge said first contact means out of engagement with said second contact means and to urge said first contact means and said carrier means to their respective first positions, said snap means comprising a flexible member operatively attached at a first part thereof to said support means and at a second part thereof operatively connected to said carrier means, said flexible member snapping from a first flexed condition to a second flexed condition at said predetermined position of said first contact means, Thereby snapping said first contact means into engagement with said second contact means, and tending to snap from said second condition to said first condition upon engagement of said first contact means and said second contact means thereby to urge said first contact means away from said second contact means, said flexible member comprising an elongated strip of material, said strip when viewed from above forming a convex curvature in one of said flexed conditions and a concave curvature in the other of said flexed conditions, said snap means further comprising a stationary member operatively connected to said support structure means and extending in the direction of movement of said carrier means from its first position to its second position, said member having a first part with a given width dimension measured in a direction substantially normal to the direction of said extension of said member, and an adjacent second part having a reduced width dimension relative to that of said first part, and a resilient member in operative engagement with said stationary member and operatively connected to said carrier means, said resilient member being moved over said stationary member by said carrier means, and being snapped from one flexed condition to a second flexed condition during its movement from said first part to said second part of said stationary member, said first and second parts of said stationary member being joined at a location such that said resilient member is snapped substantially simultaneously with the snap of said flexible member from its first condition to its second condition.
 9. The switch of claim 8, in which said resilient member comprises a spring substantially surrounding said stationary member, said spring being expanded over said first part of said stationary member when said carrier means moves from its fist position toward its second position, and being contracted over said second part of said stationary member upon the continued movement of said carrier means.
 10. The switch of claim 9, in which said carrier actuating means comprises an actuating member engaging said carrier means and effective upon the application of an actuating force thereto to move said carrier means from its first position toward its second position, said actuating member being disengageable from said carrier means when said first contact means is snapped into engagement with said second contact means.
 11. In the switch of claim 10, fist spring means operatively connected to said support means and to said carrier means and effective to aid in returning said carrier means, said resilient member, and said first contact means to their respective normal first positions after said first contact means engages said second contact means.
 12. A snap action electrical switch comprising a support means, carrier means operatively connected to said support means and movable relative to said support means from a first position to a second position upon the application of an actuating force thereto, said electrical contact means operatively connected to said carrier means and movable therewith from a corresponding first position to a corresponding second position, second electrical contact means operatively connected to said support means and effective to engage said first contact means when the latter is at said second position, and snap means operatively connected to said first contact means and effective to snap said first contact means into engagement with said second contact means when said first contact means is moved past a predetermined position between its first and second positions, said snap means comprising a flexible member operatively connected at a first part thereof to said support means and at a second part thereof operatively connected to said carrier means, said flexible member snapping from a first flexed condition corresponding to said first position of said first contact means to a second flexed condition corresponding to said second position of said first contacT means, said snapover occurring at said predetermined position of said first contact means, thereby snapping said first contact means into engagement with said second contact means, said first contact means engaging said second contact means at a position sufficiently close to said predetermined snapover position such that said flexible member tends to automatically snap back from said second flexed condition to said first flexed condition upon engagement of said first contact means and said second contact means, thereby to urge said first contact means out of engagement with said second contact means and to urge said first contact means and said carrier means to their respective first positions.
 13. The switch of claim 12, in which said carrier actuating means comprises an actuating member engaging said carrier means and effective upon the application of an actuating force thereto to move said carrier means from its first position toward its second position, said actuating member being disengageable from said carrier means when said first contact means is snapped into engagement with said second contact means.
 14. In the switch of claim 13, first spring means operatively connected to said support means and to said carrier means and effective to aid in returning said carrier means and said first contact means to their respective normal first positions after said first contact means engages said second contact means. 